CHANGE OF SPECTROSCOPIC AND STRUCTURAL PROPERTIES OF GERMANOSILICATE GLASS UNDER MECHANICAL COMPRESSION AND UV IRRADIATION

Abstract

Optical absorption, luminescence, electron spin resonance, and Raman scattering spectroscopic studies of Ge-related defects in as-made, gamma- and W-irradiated, and pressure-densified germanosilicate glass have been made. On the basis of results obtained, bistable oxygen vacancy is argued to be an adequate model for germanium oxygen-deficient centre with absorption band centred at 5.12 eV. Photobleaching of this defect is presumably accompanied by breaking of sixfold tetrahedra rings in the structure of germanosilicate glass and by creation of threefold rings.